Smart Self-Repairing System for Concrete Beams

混凝土梁智能自修复系统

• 批准号: RGPIN-2019-04285
• 负责人: Oudah, Fadi
• 金额: $ 2.26万
• 依托单位: Dalhousie University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=737534
• 关键词: Smart; Self; Repairing; System; Concrete

The Federal Sustainable Development Strategy is Canada's primary vehicle for sustainable development. It sets sustainable and resilient infrastructure as one of the key development priorities. The nation's drive for sustainability initiates the need to direct research efforts toward developing smart structural systems that adapt with mechanical and environmental loads. Smart structures mimic human muscular and nervous systems, where the system and its related component form an entity that behave in a pattern that emulates a biological function. The objective of the proposed research is to develop a smart self-repairing system for concrete beams experiencing deficiencies (cracks and excessive deformation) at normal operating loads. The system is composed of Shape Memory Alloy (SMA) wires embedded inside a reinforced concrete beam and connected to an electric current supply. The SMA is a smart material that tends to contract when subjected to heat applied via an electric current. Restraining the material by mechanical anchors at both ends will lead to the development of tension force in the SMA, and hence a post-tensioning effect. This mechanism will improve the structural performance by pulling the two sides of a crack in a concrete beam and reduce the member's deflection under applied loads. The system will be developed in three sequential stages; system design, system verification, and system reliability. The components of the self-repair system including material characterization, SMA anchorage , stress losses, and temperature effects will be examined in the first stage by small-scale testing and numerical simulation. The design recommendations pertaining to the first stage will feed into the second stage in which large scale-testing, constitutive modeling, and numerical simulation will be used to verify the system response for flexural- and shear-governed beams. The third stage is concerned with examining the reliability of using the system in the design of real-life concrete frames. The risk of adapting the new technology will be quantified using structural reliability methods and compared with the safety standards of the National Building Code of Canada. New concrete structures built with the self-repair technology will most likely not require structural repairs during their service life. This will reduce the maintenance cost of our infrastructure which accounts up to 80% of the total cost over the lifetime of the project as per the findings of a study conducted in 2015 by the Standing Committee on Transport, Infrastructure and Communities at the House of Commons. Implementing the new technology can also reduce the carbon footprint that result from producing and installing strengthening materials during structural maintenance. With the increased demand for professional engineers and researchers working in the field of sustainability, graduating HQP specialized in the broad area of structural assessment and repair is beneficial to the Canadian economy.

联邦可持续发展战略是加拿大可持续发展的主要工具。它将可持续性和弹性的基础设施视为关键发展重点之一。该国的可持续发展动力启动了将研究努力的需求，以开发适应机械和环境负荷的智能结构系统。智能结构模仿人类肌肉和神经系统，其中该系统及其相关组件形成了一个以模拟生物功能的模式行为的实体。拟议的研究的目的是为正常工作负载下的缺陷（裂缝和过度变形）开发一个智能自我修复系统。 该系统由形状内存合金（SMA）电线组成，该电线嵌入了钢筋混凝土梁中并连接到电流电源。 SMA是一种智能材料，在通过电流施加热量时会收缩。通过两端的机械锚来限制材料将导致SMA中的张力发展，从而产生后张紧效果。该机制将通过在混凝土梁中拉出裂纹的两侧并在施加的载荷下降低构件的挠度来改善结构性能。该系统将在三个顺序阶段开发；系统设计，系统验证和系统可靠性。自我修复系统的组成部分，包括材料表征，SMA锚定，应力损失和温度效应，将在第一阶段通过小规模测试和数值模拟检查。与第一阶段有关的设计建议将进入第二阶段，其中大规模测试，组成型建模和数值模拟将用于验证用于弯曲和剪切的梁的系统响应。第三阶段关注的是研究在现实生活中混凝土框架设计中使用系统的可靠性。适应新技术的风险将使用结构可靠性方法进行量化，并将其与《加拿大国家建筑法典》的安全标准进行比较。 用自我修复技术建造的新混凝土结构在使用寿命中很可能不需要结构性维修。这将降低我们的基础设施的维护成本，该基础设施占该项目一生中总成本的80％，这是根据下议院运输，基础设施和社区常务委员会在2015年进行的研究结果。实施新技术还可以减少由于结构维护过程中生产和安装加强材料而产生的碳足迹。随着对专业工程师和在可持续发展领域工作的研究人员的需求增加，HQP专门研究结构评估和维修的广泛领域对加拿大经济有益。